The present application is related to the following commonly-owned U.S. Patent Applications filed on even date herewith, the disclosures of which are hereby incorporated by reference in their entirety:
(1) U.S. patent application entitled “Surgical Stapling and Cutting Instrument With Improved Firing System” to Richard W. Timm, Frederick E. Shelton, IV, Eugene L. Timperman, and Leslie M. Fugikawa, Ser. No. 11/820,049;
(2) U.S. patent application entitled “Surgical Stapling and Cutting Instrument With Improved Closure System” to Richard W. Timm, Frederick E. Shelton, IV, Eugene L. Timperman, and Leslie M. Fugikawa, Ser No. 11/820,119;
(3) U.S. patent application entitled “Cable Driven Surgical Stapling and Cutting Instrument With Improved Cable Attachment Arrangements” to Frederick E. Shelton, IV and Richard W. Timm, Ser. No. 11/820,124;
(4) U.S. patent application entitled “Surgical Stapling and Cutting Instrument With Improved Anvil Opening Features” to Richard W. Timm, Frederick E. Shelton, IV, and Jeffrey S. Swayze, Ser. No. 11/820,077; and
(5) U.S. patent application entitled “Surgical Stapling and Cutting Instruments” to Richard W. Timm, Frederick E. Shelton, IV, Charles J. Scheib, Christopher J. Schall, Glen A. Armstrong, Eugene L. Timperman, and Leslie M. Fugikawa, Ser. No. 11/820,121.
Endoscopic surgical instruments are often preferred over traditional open surgical devices since a smaller incision tends to reduce the post-operative recovery time and complications. Consequently, significant development has gone into a range of endoscopic surgical instruments that are suitable for precise placement of a distal end effector at a desired surgical site through a cannula of a trocar. These distal end effectors engage the tissue in a number of ways to achieve a diagnostic or therapeutic effect (e.g., endocutter, grasper, cutter, staplers, clip applier, access device, drug/gene therapy delivery device, and energy device using ultrasound, RF, laser, etc.).
Known surgical staplers include an end effector that simultaneously makes a longitudinal incision in tissue and applies lines of staples on opposing sides of the incision. The end effector includes a pair of cooperating jaw members that, if the instrument is intended for endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. One of the jaw members receives a staple cartridge having at least two laterally spaced rows of staples. The other jaw member defines an anvil having staple-forming pockets aligned with the rows of staples in the cartridge. The instrument commonly includes a plurality of wedges that, when driven distally, pass through openings in the staple cartridge and engage drivers supporting the staples to effect the firing of the staples toward the anvil.
An example of such surgical staplers is disclosed in U.S. Patent Publication No. US 2006/0011699 A1 to Olson et al., the disclosure of which is herein incorporated by reference. The stapling devices disclosed therein employs a cable or cables that are positioned around distally located pins or pulleys and are fixed to the knife. The ends of the cables are pulled in a proximal direction. Such system, however, suffers from a low mechanical advantage and tends to require relatively high forces to pull the knife through its stroke.
Thus, there is a need for an improved drive and firing system for use with cable driven surgical staplers.
In addition, such cable fired surgical stapler systems may suffer from the inadvertent disengagement of the cable from the pulley system which may disable the device. This condition may be caused by mechanical vibration during use or other shock forced encountered during use or shipping.
Thus, there is another need for apparatuses, devices and systems for ensuring that the cable or cables used to fire a surgical stapling device do not become disengaged from their respective pulleys or drive members.